US2546029A - Side bearing for car trucks - Google Patents

Description

March 20, 1951 o. T. GREGG 2,545,029

- sma- BEARING FOR CAR TRUCKS Filed March 5, 1946 2 Sheets-Sheet 1 \IHHHII I- HH II I fi H 2 llllll I nllllm Him. JH HIII HII In HIHIII HIHH IN VEN TOR. 0775' Z' GREGG W WW Y MATTUEZVE'K? March 20, 1951 o. T. GREGG 7 SIDE BEARING FOR CAR TRUCKS Filed March 5, 1946 2 Sheets-Sheet 2 Patented Mar. 20, 1951 SIDE BEARING FOR CAR TRUCKS Otis T. Gregg, Hackensack, N. J assignor to The Gregg Company, Ltd., New York, N. Y., a corporation of New York, and to Gregg Car Company,Ltd., Panama, R. P., a corporation of Panama Application March 5, 1946, Serial No. 652,146

9 Claims.

This invention relates to improvements in antifriction types of side bearings for railroad cars.

A railroad car of the conventional type has a long rectangular underframe or platform which rests on two trucks, one being situated near each end of the car. The platform is carried on the trucks by means of center bearings situated on laterally extending truck bolsters.

To keep the underframe balanced so that it will not tilt substantially, side bearings including bearing elements on the truck bolsters and on the underframe are placed some distance apart laterally of the truck bolsters, with approximately one-eight inch clearance between the bearing elements. Tilting of the car body relatively to 2 ward motion exceeds the slight clearance between the bearing elements, the roller will bind between the supporting member and the car frame bearing element during turning movements of the car truck and resist turning of the truck.

Moreover, the car trucks, during normal operation, are subjected to continuous vibration from the rail joints and because of other irregularities in the track. As a result, the rollers of the bearings are subjected to vibration which may be of the same fundamental frequency as, or a harthe truck bolsters is limited by the clearance between the side bearing elements.

When the railroad cars travel on curves, the trucks must turn to suit the curves of the track. This turning motion is permitted by the center bearing. bearing elements which may or may not be in contact, move with respect to each other. If they are in contact, then such relative motion results in friction. To reduce the friction, railroad cars sometimes are equipped with roller side bearings.

The roller type of side bearing often consists of a solid cylindrical roller that is usually supported on the bolster and is arranged to roll a limited distance in a direction parallel to the rails. The roller usually is supported on a plate having a slightly concave surface so that the roller normally has a tendency to return to its center position when the roller is out of engagement with the bearing element on the underframe. However, the roller must be moved a substantial distance from its center position before there is any substantial tendency for it to return to its center position.

Since most curves on railway tracks are very slight, it follows that under most conditions only a slight movement of the roller out of its center position will take place and corespondingly there is only a very slight tendency for it to return to its center position when it is disengaged from the side bearin element carried by the car underframe. As a result, the roller may be already displaced from its center position when it engages the underframe bearing element and will be unable to travel longitudinally a sufficient extra distance to permit free turning of the car truck when curves are being negotiated.

Another disadvantage of the use of a concave support for the roller is that it causes the roller When such turning occurs, the side to rise upwardly as it moves from a center position toward the ends of the support. 7 If this upmonic of the natural frequency of, the roller and the roller may be set into motion in the bearing box, rolling back and forth at the frequency set up by the vibration. Therefore, when the car rounds a curve, the roller may become engaged with the upper bearing element on the car underframe when the roller is near the end of its limited path of travel. The roller then exerts a drag, with the result that turning of the truck is hindered and a flat may be Worn on the roller. If this occurs frequently, the roller will be so distorted that it will not roll smoothly even when it engages the upper bearing element while in its center position, thereby resisting the turning movement of the car truck relatively to the car underframe.

An object of the present invention is to provide roller or anti-friction type side bearings which are capable of rolling or rocking movement without rising and which are self-centering.

Another object of the invention is to provide anti-friction side bearings that are self-centering and which can be used with a flat supporting element to avoid change in the clearance between the bearing elements.

A further object of the invention is to provide a side bearing of the anti-friction or rocking type that permits additional turning of the car truck relatively to the car frame without damage to the bearing even when the turning exceeds the amount afiorded by the limited travel of the roller or rocker.

Another object of the invention is to provide a side bearing construction for car trucks in which the bearing member is not responsive to vibrations set up during the operation of the truck so that it will always tend to remain in its center position ready to permit relatively frictionless turning of the truck relative to the car body.

Another object of the invention is to provide a vibration damping mechanism and centering means for side bearings of car trucks and to provide a bearing of novel form which is self-centering.

Other objects and advantages of the invention of the rocker.

3 will become apparent from the following description of typical forms of side bearings embodying the present invention.

The objects of the invention are attained by the provision of a novel type of self-centering roller or rocker Whichcan be supported by a flat plate so that the roller or rocker does not rise as it rolls.

More particularly, side bearings of the type embodying the present invention'may 'be'provided with rollers or rockers that are provided with relatively movable stabilizing means, ;such as a weight or weights which are arranged so that when the rocker or roller rocks, its upwardly moving portion lifts the weight or a portion of it and its downwardly-moving-portion is relieved of the weight. Thus, the roller or rocker is rendered unbalanced and tends to return to'its initial position.

More particularly, the'rocker of the side bearingmay be provided withione or more eccentric portions that engage or carry a relativel movable weight or weights which are also supported by the bearing plate or box on the car truck bolster. The eccentric portion or portions are normally disposed in such a position that upward movement thereof lifts a weight and downward movement of the eccentric portion substantially disengages it from a weight. In this way, even a slight rocking movement Of the rocker unbalances it and tends to return it to its center position.

A preferred form of :the device is a rocker provided withoutwardly extending arms having flat surfaces tangent to the surface of the rocker so that if the turning movement of the truck is greater than would normally be afforded by the rolling motion of the rocker, the truck can turn farther by relative sliding movement between fiat surfaces on the rocker and the .car body. Inasmuch as the fiat surfaces areof substantial area, the friction between the contacting surfacesis not excessive and the turning movement of the car truck is not substantially hindered.

The stabilizing means,'being relatively movable with respect to the rocker, also absorbs vibrations set up in it and thereby acts as a vibration damper to prevent rocking Of the rocker in response to such vibrations. During harmonic motion of the rocker, the stabilizing means is alternately lifted and restored to its support. Also, the relative movement of the stabilizing :means and the eccentric portion of the rocker introduces considerable friction. This relative movement and friction act to absorb the vibration and change the .fundamental frequency'of the rocker repeatedly and thus damp the harmonic motion This damping effect is present whether the rocker is moved substantially or only very slightly from its center position.

For a better understanding of the present invention, reference may be had to the accompanying drawings inlwhich:

Figure l is a plan view of a typical bearing member embodying the invention;

Figure 2 is a view in section taken online 22 of Figure 1;

Figure 3 is a side view of a modified form of rocker embodying the present invention;

Figure 4 is a side view of a modified form of bearing member embodying the invention with the bearing box shown in section;

Figure 5 is a plan .view of the bearing shown in Figure 4; and

Figures :6 and 7 are side'views of other forms upper surface-of acar truck bolster, or formed as a ;part thereof. The bottom of the bearing box it} may be :provided with a hardened steel supporting orbearing plate H which is substan tially flat from end to end and from edge to edge.

A rocker member l2 of cylindrical shape is rockably :mounted in the bearing box and is adapted to engage a bearing plate It on the undersurface :ofqa ,cross member on the car under- .frame, not shown. ,NQrmaIlya-clearance of about one-eighth'of an inch, more or less, is provided between the member ;|2 and the plate is.

The rocker member 12 is designed to be .constantly centered whereby it is always in position to afford relatively frictionless turnin of the bolster relative to the car underframe. The rocker member 12 'mayihavea radius of about two and one-half inches although the length of the radius and the .shapeof the rocker member can be varied, depending upon requirements.

As illustrated, the rockermember I2 has a pair of diametrically spaced pinsl i and i5 eccentric to the axis ,of the rockermember and projecting from one .of its ends which are adapted to engage an elongated stabilizing member it in the form of a'bar of steel, iron orxthe like. The ends of the stabilizing member l6 rest upon the pins i? and 1-8 that extend inwardly from a side of the bearing box Hi. It will be understood that the above-describedarrangement can be duplicated at the opposite end of therocker member l2 or that al-singlebar havingan opening in its mid-portion for receiving the rocker member 12 can be used instead of't'he bar f6. Also the pinsil' tand I 5may be connected bymeans .ofa web forming, ineffect, a continuous platform for supporting the bar H3.

The action :of theiabove-described bearing con struction is1as .follows.

When the rocker member t2 rolls from the pcsitiontshown in Figure 1, forexample, toward the right, the .pin. 44 moves clockwise and upwardly while thepin 1.5 moves downwardly. The pin. in moving upwardly lifts the left-hand end of thebar :l 6 and the banpivots around the pin 18. The pin 14 is .subjected to a part of the weight of the bar It, and inasmuch as the pin M is eccentric to the rockermember |2,"it is rendered unbalanced and willtend to rock to'the left thereby returning to its center position.

Rocking or rolling I movement of the rocker member l2 to the left produces the same effect, but in this case, the pin ['5 lifts the bar 18 which pivots about the pin 11. Therefore, 'movement of the rocker member l2 in eitherdirection'is opposed by the stabilizing member 16, and most strongly when the displacement ofthe rocker member is slight, thereby assuring the centering of the rocker member #2 under all operating conditions.

The stabilizing means described above and'the stabilizing means described hereinafter also act effectively as vibration dampers. It will be clear that as the bar-l6, for example, is raised and lowered, it changes the effective mass of the rocker member l2 and also introduces some frictional resistance to movement of the rocker member. The vibrations thus are absorbed frictionally and by the work done in lifting the bar it. Also the fundamental frequency of the rocker member is changed by the change in its effective mass and the rocker member is rendered less responsive to vibrations at a fixed frequency and its harmonics.

Figure 3 of the drawings discloses another form of rocker member and stabilizing and vibration damping means. The cylindrical rocker member 20 is provided with diametrically spaced arms 2! and 22 which are provided with the transverse holes 23 and 24. Loosely mounted in the holes 23 and 24, respectively, are the rivet- like pins 25 and 26 which are of such length that their lower ends substantially engage the supporting plate 21 when their heads 25a and 26a are in engagement with the upper surfaces of the arms 2| and 22.

The rocker member disclosed in Figure 3 cperates similarly to the rocker member l2, in that when the rocker member 2 rolls toward the right,

the pin is lifted while the arm 22 is relieved of the weight of the pin 26. The weight of the pin 25, therefore, acts to restore the rocker member 26 to its center position. Similarly, the pin 28 acts to restore the rocker member to its center position when it moves toward the left.

The rocker member of the side bearing does not have to be cylindrical and in the preferred forms of the invention, the rocker members are provided with semi-cylindrical mid-portions, and fiat surfaced arms tangent to the semi-cylindrical portions.

As shown in Figures 4 and 5 one form of the preferred type of rocker member 30 may have a semi-cylindrical mid-portion 3| (semi-cylindrical upper and lower surfaces) and laterally projecting arms 32 and 33 which are provided with the outwardly converging flat surfaces 34, 35, 36 and 31. These surfaces are tangent to the surface of the mid-portion 3| and may be inclined at an angle to the horizontal sufficient to permit the rocker member 30 to rock through an angle large enough to accommodate the normal turning movements of the car trucks. However, if,

under unusual conditions, a greater turning of the truck is required, sliding movement can take place between the surfaces 34 or 36 and the hearing element on the underframe on the car, in which case, the friction is not excessive because of the large surface areas then in contact.

Inasmuch as the rocker member 30 is supported on its semi-cylindrical mid-portion 3|, it would under certain conditions of proportioning have a tendency to tilt and fall over so that one of its surfaces or 31 would rest against the supporting member 38. In order to overcome this tendency and also to damp vibrations which would tend to set the rocker member into rocking movement, and also to return it to its normal center position, a generally U-shaped stabilizing member 39 is mounted in an opening that extends lengthwise of the rocker member 30 and through its undersurfaces 35 and 31. The ends 39a and 39b of the member 39 are normally substantially in engagement with the supporting member 38 when the mid-portion 390 of the member 39 is in engagement with a flat inner surface 4| forming the bottom of the opening 40. The opening 40 is shaped so that the stabilizing member 39 can be completely inserted into the opening 40.

The member 39 is of such weight that it will tend to retain the rocker member 30 in its center position. When the rocker member 30 tends to rock in one direction or the other, it lifts one end of the stabilizing member 39 and is relieved of the weight of the other end of the member 39. The stabilizing member 39, also, being movable relatively to the rocker member 39 will absorb vibration in the manner described above.

The above-described rocker member 30 may be provided with means for preventing it from sliding along the supporting member 38, if desired. Thus, for example, as shown in Figures 4 and 5, the rocker member 30 is provided at opposite sides with laterally projecting lugs 42, each of which is situated at or near the bottom of the rocker member 3 and at or near its center. The lugs 42; 42 are received in channels 43 and 44 in opposite sides of the bearing box 45 and thus prevent substantial endwise sliding movement of the rocker member 30.

The rocker member 30 and its stabilizing means can be modified considerably, as illustrated in Figures fi and 7 of the drawings. In Figure 6 the rocker member 59, which is of a shape similar to the rocker member 30, described above, is provided at its opposite ends with substantially vertical apertures 5| and 52 in which are mounted loosely the rivet-like weights 53 and 54. These weights are slidable relatively to the rocker member 59 and act in the same way as the weights 25 and 25 disclosed in Figure 3. Y

The stabilizing means for the rocker member is susceptible to still further modifications and may be arranged as shown in Figure '7. In this form of the invention, the rocker member 6|] has contours like the rocker members 3 and and includes the arms 6| and 62. The arms have the grooves 33 and 64 therein which extend substantially vertically along the lateral surfaces of the arms and horizontally across the tops of the arms. U-shaped weights 65 and 66 are mounted loosely in and are substantially complemental to the grooves 63 and 64. The ends of the weights and 66 are substantially in engagement with the supporting member 61 when the weights are both suspended from the arms 6| and 62 of the rocker member 65. The U-shaped weights, therefore, are supported eccentrically of the axis of the rocker member and act like the stabilizing members described above in returning the rocker member an to its center position and in damping vibration of the rocker member 60.

Each of the rocker members 50 and 60 may be provided with lugs like the lugs 42 of the rocker member 30.

From the preceding description of a typica form of side bearing embodying the present invention, it will be apparent that I have provided anti-friction bearings that facilitate the turning movements of car trucks and avoid the difficulties encountered with plain or roller bearings of the type used heretofore.

It will be understood that the side bearings embodying the present invention are susceptible to considerable further modification of their size, shape and other structural details without departing from the invention. Therefore, the form of the invention described above should be considered as illustrative and not as limiting the scope of the following claims.

I claim:

1. A side bearing for railroad cars comprising a rocker member having semicylindrical upper and lower surfaces, means supporting said rocker .memberzfor Iockingimovement, stabilizing means having'weight portions i'onopposite sides of the axisoi said trock'er -member, and substantially diametrically spaced elements .:on said rocker member eccentric to'the axis oflsaid rocker memher for lifting one ofsaid weight portions upon rocking movement of said rocker member from an initial-position, :whereby theliited weight portion urges-said rocker member toward said initial position.

2. A 's'ide bearing for raiiroad o rs, coup-rising arocker member having semicy drical and lowersurlEa-ces, means supporting said rocker member on its lower semicylindri'ca'l surface iior rocking movement in opposite directions from an initial position, weight means having portions on-opposite sides *of the axis of said rocker member,'-substantiallydiametrically spaced means on said rocker member engaging said weight means for lifting one of said portions upon rocking movement of said rocker member from said initial position; whereby the weight of said lifted portion urges said rocker member toward said initial position.

3. A side'bearing for railroad cars, comprising a rocker member having semieylindricai upperzand lower surfaces, arms projecting outwardly-rrom opposite sides or" said rccser member, and weight meansshiftable relatively to said rocker 'member and carried by said for stabilizingsaid rocker member.

4. A side bearing for railroad car trucks, comprisinga bearing boX adapted to be mounted on a car truck, arocker member in said box, rocker member having upper and lower semicylindrical portions, arm's projecting outwardly from opposite sides or" said rocker member and having upper and lower outwardly converging flat sides tangent to said surface portions, and Weight means movably carried by said arms and :engageable. and disengageahle with said bearing box on opposite .sides of said rocker member for stabilizing the latter and dampening its vibrations;

'5. Aside bearing for railroad cars comprising a bearing box adapted to be mounted on a car truck, a rocker member in said said rocker member having upper and lower semicylindrical surface portions, arms on and projecting outwardly in opposite directions from said rocker .member, and weight means carried b said arms lindrical upper-sandflower ;surfacesi rockablysup ported on the bottom of saiclibox and havin outwardly iprojecting arms on :its opposite :sides, means forming ,,,passages in :said arms substam tially perpendicular to said'arms, weightvmembers slidablyrmounted in :saidpassages, landcooperating "means on said weight members and said arm for limiting downward movement of said weight members.

7. A side bearing for railroad cars, comprising a rocker member vhaving semicylindrical upper and lower surfaces, a substantially -U-shap'ed weight member mounted within said rocker-membar and having a .midportion anti downwardly projecting arms at its opposite ends, and means Within said rocker member "engaging :said midportion for suspending said 'U-shaped member for movement relatively to said rocker member.

8. A side bearing for railroad cars-comprising a box-like member adapted to be mounted on a car truck, a rocker member having upper and lower semicylindrical surfaces and arms extending in opposite directions therefrom, said rocker member being rockably mounted in said box'so that one arm moves upwardly while the other moves downwardly, said rocker member having an aperture extending therethrough lengthwise of said arms and opening downwardly toward the bottom of said box-like member, a U-shaped weight member loosel mounted in said opening and having :downwardly extending ends engageable with the bottom of said box-likemember, said weight member being movable relatively to said rocker member to allow rocking .-movement of the latter while exerting :a downward thrust on the upwardly moving arm and relievingthe opposite arm of downward thrust.

A side bearing for railroad cars comprising a rocker member having semi--cylindrica1 upper and lower surface portions and arms having outwardly converging flat surfaces on opposite sides of and tangent to said semi-"cylindrical portions, means supporting said rocker member for rocking movement on said semi-cylindrical portions, means on-oneof said rocker members forcentering it on said supporting means, and weight means movably carried by said arms for stabilizing said rocker member anddampeningits vibrations.

OTIS T. GREGG.

REFERENCES CITED The :following references are of record in the file of this patent:

UNITED STAT-ES PATENTS Number Name Date 1,360,781 OConnor N0v330, 1920 1,6409% Haseltine Aug.'23, 1927 1,660,444 Haseltine Feb.- 28, 1928 1,674,821 Geiger June "26, 1928 1,796,300 OConnor Mar. 17, 193i

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